Percutaneous coronary intervention for chronic total occlusion of the left circumflex branch in mirror dextrocardia: a case report.

BACKGROUND: Mirror dextrocardia (MDC) is a condition in which the heart is located in a mirror-image position on the right side of the chest compared to the normal position in individuals with physiological variations. Patients with MDC and chronic total occlusion (CTO) of the left circumflex branch (LCX) are extremely rare in clinical practice. The treatment of MDC-CTO-LCX differs significantly from patients without mirror dextrocardia and the same condition in terms of instrument selection and procedural techniques. In this article, we report a successful case of interventional treatment in a patient with MDC-CTO-LCX. We summarize the anatomical and electrocardiographic variations in patients with MDC-CTO-LCX, and discuss the selection of interventional instruments and techniques that can be useful for interventionists as well as the diagnostic and therapeutic considerations that can be helpful for clinical physicians. CASE PRESENTATION: A male Han Chinese patient, 51, was admitted, presenting recurrent chest pain for a year and recent onset of exertional fatigue over the past week.He reported episodes of chest pain following physical activities over the past year, lasting between 5 and 20 min.Despite these symptoms, the patient did not seek immediate medical attention, and the occurrence of his chest pain has progressively lessened within the year.A week prior, the patient developed exertional dyspnea after brief walks, though without any episodes of nocturnal paroxysmal dyspnea.Upon arrival at our hospital for evaluation, he was initially diagnosed with chronic coronary syndrome, previous inferior myocardial infarction, atrial arrhythmia, and classified under the New York Heart Association functional class III.Following his admission, a chest X-ray and coronary angiography were conducted.The results indicated mirror dextrocardia and total occlusion of the left circumflex branch. Percutaneous coronary intervention (PCI) was performed on the left circumflex branch. Subsequent angiography demonstrated optimal stent positioning without evidence of hematoma or dissection.Following the procedure, the patient's symptoms of chest pain and exertional dyspnea were resolved, which led to his subsequent discharge.A follow-up electrocardiogram, 10 months post-procedure, displayed a slow and regular atrial rhythm. CONCLUSIONS: The incidence of dextrocardia is very low, and it may appear normal on an electrocardiogram; however, careful diagnosis is required when there is an abnormal direction of the P wave in limb leads. During the operation for chronic occlusive lesions of the right-sided coronary artery, the anomalous anatomical structure necessitates specific requirements for instrument selection and operative techniques. After revascularization of chronic occlusive vessels in dextrocardia, routine electrocardiographic examination may show false normalization, requiring caution in interpretation.

Homocysteine mediates cardiomyocyte apoptosis by phosphorylating PERK and activating CHOP-ERO1α pathway / 重庆医学

Objective To investigate the effects of homocysteine(Hcy) on myocardial injury and its possible mechanisms.Methods The selected H9C2 cardiomyocytes were intervened with various concentrations of Hcy and 4-phenyl butyric acid(4-PBA).The H9C2 cells were divided into the control group,H400 group and H400P2 group.The control group used the common medium,the H400 group was added with 400 μmol/L Hcy,the H400P2 group was added with 2 mmol/L 4-PBBA on the basis of H400 group.The cell livability was detected by using cell counting kit-8 (CCK-8).Apoptosis was evaluated by using the terminal deoxynucleotidyl transferase mediated nick-end labelling(TUNEL) staining.The ERO1α expression was determined by using immunocytochemistry,and the protein expression difference was determined by using Western blot.Results The injury of Hey on H9C2 cardiomyocytes showed a concentration-dependent manner(F=2 039.958,P＜0.01).Compared with the control group,the apoptosis percentages and expression levels of PERK,p-PERK,CHOP and ERO1α in the H400 group were increased(P＜0.01);while which in the H400P2 group were decreased,the difference was statistically significant(P＜0.05).Conclusion Hcy mediates myocardial apoptosis through endoplasmic reticulum stress mechanism.